10GrandSport

I am exploring options in regards to subwoofer set-ups, and I really would like to get a 12 or two in the car. I also need the ability to store the roof. Any suggestions?

0Double D Mods

not going to easily happen as you can not get a 12" into the corners and would need to put it directly behind the seats in a custom box.
Your much better off with 2 10's anyways in my eyes. You could do a custom 12 inch coupe box but would only be able to use shallow 12" subs due to mounting depth.
10's are awesome and I have 3 options for boxes for you.
Jl 10w3
Arc 10
Focal P25DB

markcz

One well powered 10" is plenty in a vette. I'm feeding 350wRMS to a single Arc10D2 in a Vettenuts enclosure (both from Dennis). It sounds great and has no problem at all keeping up with the ~540w in the doors (details in sig).

jdmvette

12s are pretty easy in a c5. not so sure about your grand sport.